Though prior art workers have given much attention to preliminary treatment of foodstuffs, and particularly to such treatments as drying, less work has been done in the area of liquid treatments of the type necessary to accomplish rehydration. Thus, the workers in the food art have long been able to dry, and especially freeze dry, proteinaceous foodstuffs such as shrimp, but the problem of rehydration has usually been left to the ultimate customer and has largely centered on what might be termed kitchen methods. As a result, the market for freeze dried products, for example, has tended to be limited to applications where the dried product is to be cooked by the customer and the deficiencies of rehydration are thus masked. Only in recent times, as exemplified by my prior U.S. Pat. Nos. 3,760,716, issued Sept. 25, 1973, and 3,804,959, issued Apr. 16, 1974, has attention begun to be focused on the problems of liquid treatments of the type involved in rehydrating freeze dried foodstuffs.
If freeze drying of foodstuffs such as shrimp is to become a viable preparatory method, it is necessary that rehydration methods and apparatus be provided which can be employed at each market center and will produce a rehydrated product which is organoleptically similar to the fresh foodstuff. The fact that the rehydrated product is ordinarily handled as if the product were fresh tends to minimize the size of rehydration plants. While my earlier U.S. Pat. No. 3,760,716 provides rehydration apparatus useful when the rehydration plant is to have a relatively large output, no completely satisfactory method and apparatus suitable for relatively small market areas has heretofore been provided.